1. Field of the Invention
The present invention relates to a composite operation type input device which is capable of carrying out an input operation with two different pressing and rotation operations.
2. Description of the Related Art
Heretofore, as an example of this type of composite operation type input device, there has been known a device which comprises a rotary operation unit having an annular rotary knob, a slider which is rotated by this rotary knob, a printed board having a contact point pattern in sliding contact with this slider, a pressing operating unit having an operation shaft which can move vertically on the inner side in the radial direction of the rotary knob, and a push switch which is pressed by an end of this operation shaft and mounted on the printed board.
In the composite operation type input device which is constituted as described above, when an operator rotates the rotary knob, the slider rotates together with the rotary knob and moves the contact point pattern on the printed board, whereby a rotation operation detection signal corresponding to the contact position between the slider and the contact point pattern is output. When the operator presses down the operation shaft by a predetermined stroke, the actuator of the push switch is pressed down by the end of the operation shaft, whereby a movable contact point incorporated in the push switch contact a fixed contact point to output a pressing operation detection signal.
In the above conventional composite operation type input device, the rotation operation mechanism including the rotary knob and the pressing operation mechanism including the operating shaft are separated from each other so that they can act independently without interfering with each other. However, when these two independent operation units are installed adjacent to each other in a limited space, the resulting structure becomes complicated, thereby making it difficult to cut the cost. Further, since a part to be rotated is mounted around a part to be pressed, it is difficult to prevent an increase in the diameter of the rotation operation mechanism with the result that the whole device becomes large in size. Further, when the rotation operation is repeated, the contact sites of the slider and the contact point pattern gradually wear away, thereby making it difficult to maintain desired detection accuracy for a long time.